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Licensed Unlicensed Requires Authentication Published by De Gruyter (O) September 25, 2009

Solid-Solid Phase Transition in Trimethylolpropane (TRMP)

  • D. Chandra , H. Mandalia , W.-M. Chien , D. W. Lindle and R. Rudman

An orientationally disordered crystalline (ODIC) plastic phase (γ) was observed in Trimethylolpropane (TRMP) during heating by high resolution thermal and X-ray diffraction analyses. TRMP is a potential thermal energy storage material. The enthalpies of solid-solid (α → γ at 327.8 K) and fusion (γ → liquid at 332.7 K) transitions are 16.36 kJ/mol and 0.9 kJ/mol, respectively. Supercooling was observed during solidification of melts, and this supercooled γ phase began to transform to a metastable crystalline phase, designated as α′, after 20 minutes at room temperature. The lattice parameters of the monoclinic α phase, obtained from this study, are: a = 0.8427(5), b = 0.9580(5), c = 0.9185(6) nm, β = 98.958(3)° @ 298 K with Z = 4. The ODIC high temperature FCC γ phase has a lattice parameter: a = 0.9274(3) nm @ 328 K with Z = 4. Differential scanning calorimetry, in-situ Bragg-Brentano X-ray diffractometry, and high temperature and resolution Guinier X-ray diffraction systems were used to determine these phase transitions.

Published Online: 2009-09-25
Published in Print: 2002-12
Downloaded on 19.3.2024 from https://www.degruyter.com/document/doi/10.1524/zpch.2002.216.12.1389/html
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